Transit concrete mixer



Oct. 18, 1966 F. v. MENDOZA 3,279,766

TRANS IT CONCRETE MIXER Filed April 6, 1965 2 Sheets-Sheet 1 7 7M 24, 171a J.

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Oct. 18, 1966 F. v. MENDOZA 3,

' TRANSIT CONCRETE MIXER Filed April 6, 1965 2 Sheets-Sheet f3 54- I flea yfMs/voozz;

United States Patent 3,279,766 TRANSIT CONCRETE MIXER Fred V. Mendoza, Anaheim, Calif., assignor of fifty percent to William C. Thomas, Arcadia, Calif. Filed Apr. 6, 1965, Ser. No. 445,991 7 Claims. '(Cl. 259-172) The present invention relates generally to improvements in transit concrete mixers; more particularly, the invention relates to novel remotely controllable means for releasably retaining the concrete discharge chute of a transit mixer in fixed angular position.

A typical transit concrete mixer comprises a self-propelled vehicle rotatably mounting a motor-driven mixing drum. In one end of this drum is an opening through which the concrete ingredients are initially introduced into the drum and through which the final concrete slurry is discharged from the drum. The drum contains internal helical vanes which are effective to mix the ingredients into a concrete slurry during rotation of the drum in one direction and to convey the slurry through the discharge opening of the drum during rotation of the latter in the opposite direction. Such a transit mixer is commonly equipped with a chute which receives the slurry emerging through the drum opening, and conveys the slurry to a position beyond the vehicle frame. In most cases, the drum end of this chute is rotata'bly mounted on the vehicle frame for turning about a normally vertical axis, thereby to permit the discharge end of the chute to be swung from one side of the vehicle to the other.

Most conventional transit mixers are not equipped with any means for securing or locking the discharge chute in fixed angular position. Accordingly, it is necessary to manually retain the chute in fixed position. This manual retention of the chute in fixed position is undesirable for the reason that it requires services of a man who might otherwise be performing a more valuable task. Also, manual retention of the chute creates the possibility of inadvertent release of the chute and consequent injury to personnel or property in the vicinity of the transit mixer. Moreover, the chute may not be properly secured when the mixing drum is emptied, with the result that the chute may accidentally swing and cause injury or damage while the transit mixer is in motion. There is, accordingly, a need for a practical means of releasably locking the chute in fixed angular position.

It is therefore a general object of the present invention to provide novel means for releasably locking in fixed angular position the concrete discharge chute of a transit mixer.

An object of the invention is the provision of novel chute locking means of the character described which may be controlled either from the drivers cab of the transit mixer or from a position adjacent the chute.

A further object of the invention is to provide novel chute locking means of the character described which is relatively simple in construction, economical to fabricate, reliable in operation, and simple to install, even on existing conventional transit mixers.

Other objects, features and advantages of the present invention will become apparent to those versed in the art from a consideration of the following description, the appended claims and the accompanying drawings, wherein:

FIGURE 1 is a perspective view of a transit concrete mixer embodying the novel discharge chute locking means of the invention;

FIGURE 2 diagrammatically illustrates the control system of the chute locking means;

FIGURE 3 is an enlarged section, taken on line 33 of FIGURE 1, through a brake mechanism embodied in the chute locking means; and

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FIGURE 4 is a further enlarged exploded perspective view of the brake mechanism in FIGURE 3.

In FIGURE 1 of these drawings there is illustrated a transit concrete mixer 10 which is generally conventional. This transit mixer comprises a truck 12 having a forward drivers cab 14 and a rear bed 16 on which is rotatably supported a concrete mixing drum 18. The forward end of the mixing drum is drivably coupled, through a chain drive 20, to an auxiliary engine 22 mounted on the truck bed 16, whereby the drum may be driven in rotation from the auxiliary engine. Associated with the auxiliary engine are controls (not shown) which may be selectively operated to disengage the drum from the auxiliary engine and to effect driving of the drum in either direction of rotation by the engine. In the rear end of the mixing drum 18 is a discharge opening (not shown) through which the concrete ingredients are initially introduced into the drum and through which the final concrete slurry is discharged from the drum. The rotation axis of the mixing drum commonly inclines upwardly toward the rear open end of the drum, as illustrated in the drawings.

Mounted on the rear end of the truck bed 16 in a position adjacent the rear opening in the mixing drum 18 is a hopper 24, the upper end of which is opened and the lower end of which communicates with the rear opening in the mixing drum. The concrete ingredients are introduced into the mixing drum to this hopper. Contained within the mixing drum are helical vanes (not shown) which are effective, during rotation of the drum in one direction, to mix the ingredients into a concrete slurry. Generally, the drum is driven in this mixing direction, thereby to agitate the slurry, during travel of the transit mixer from the supply yard to the job site. During rotation of the drum in the opposite direction, the internal mixing vanes in the drum convey the slurry through the rear opening in the drum. Mounted below the hopper 24 is a discharge chute 26, the upper or drum end of which is disposed to receive the concrete slurry as the latter emerges through the rear opening in the drum. The lower discharge end of this chute is located outboard of the truck body, whereby a suitable receiver (not shown) may be placed below the discharge end of the chute to receive the slurry therefrom. In accordance with conventional practice, the upper end of the discharge chute 26 is rotatably mounted by means 28 for turning about a normally vertical axis 30, thereby to permit the lower discharge end of the chute to be swung from one side of a truck 12 to the other.

The transit concrete mixer 10, as it is thus far described, is conventional. This invention provides a means 32 for releasably locking the chute in fixed angular position about its rotation axis 30. Locking means 32 comprises a brake mechanism 34 which is shown in detail in FIG- URES 3 and 4. The brake mechanism is supported on the bracket 36 located in line with the upper end of the chute 26 and rigidly secured to the truck bed 16. At the rear end of the mounting bracket 36 is a bearing sleeve 38, the axis of which approximately coincides with the rotation axis of the discharge chute 26.

Brake mechanism 34 includes a mounting plate 40 which is notched at 42 to straddle, in the manner illustrated in FIGURE 3, the mounting bracket 36 and its bearing sleeve 38. The mounting plate 40' is welded or otherwise rigidly joined to the mounting bracket 36. R0- tatably fitted in the bearing sleeve 38 is a shaft 44. Shaft 44 is restrained against axial movement in the bearing sleeve 38 by means of a shoulder 46 on the shaft above the bearing sleeve and a cross pin 48 in the shaft below the bearing sleeve. The lower end of the shaft 44 extends some distance below the lower end of the bearing sleeve 38 and is machined to form a fiat sided tongue 50 on the shaft. Indicated at 52 is a strut which connects the lower end of the shaft 44 to the lower discharge end of the discharge chute 2-6. This invention is not concerned with the construction of the connecting strut 52 except insofar as the latter is arranged to provide a connection between the shaft 44 and the chute 26 in such nature that the chute may be restrained against rotation on its turning axis 30 by retention of the shaft 4-4 against rotation. However, it is common practice in transit mixers to attach to the discharge chute a connecting strut, similar to the strut 52, which comprises a hydraulic piston and cylinder for elevating and lowering the discharge end of the chute. For this reason, the connecting strut 52 illustrated in the drawings is shown to comprise such a hydraulic chute elevating piston and cylinder. Accordingly, it is assumed that the chute connection 28 not only permits rotation of the chute about its vertical turning axis 30 but also rotation of the upper end of the chute about an axis transverse to the turning axis 30, thereby to permit the discharge into the chute to be raised and lowered. The cylinder 52a of the connecting strut 52 has a bifurcated end 54 which straddles the tongue 50 on the shaft 44, and is pivotally secured to the shaft by a bolt 56. The piston rod 521) of the connecting strut 52 is pivotally attached to a band 58 secured to the lower discharge end of the chute 26.- Extending from the end of the cylinder 52a adjacent the pivot shaft 44 is a hose 60 through which the latter end of the cylinder may be selectively supplied with hydraulic fluid under pressure and vented to raise and lower the chute.

At this "point, it is apparent that rotation of the discharge chute 26 about its turning axis 30 rotates the pivot shaft 44 in the bearing sleeve 38. It is further apparent that retention of the pivot shaft against rotation is effective to lock the discharge chute in a fixed angular position about its turning axis. The brake mechanism 34 is efi'ective to thus releasably restrain the pivot shaft 44 against rotation, thereby to lock the chute in fixed angular position. To this end, the brake mechanism 34 comprises a conventional hydraulic vehicle brake including a supporting disc 62 which is welded or otherwise rigidly secured to the brake mechanism mounting plate 40. On top of the supporting disc 62 are a pair of semi-circular brake shoes 64, adjacent ends of which are pivotally mounted, by the usual brake shoe mounting means 66, on the disc 62. The opposite ends of the brake shoes are connected by the usual hydraulic brake cylinder 68 and brake shoe retraction springs 70. Extending from the brake cylinder 68 is a hose 71 through which hydraulic fluid may be admitted to the brake cylinder, thereby to move the adjacent ends of the brake shoe 64 outwardly against the action of the springs 70. Fitted over the supporting disc 62 and the brake shoe 64 is a conventional brake drum 72. This brake drum is secured, by bolts 74, to a mounting flange 76 welded or otherwise rigidly joined to the upper end of the pivot shaft 44. It is apparent at this point, therefore, that admission of hydraulic fluid to the brake cylinder 68, through its hose connection 71, is effective to urge the brake shoes 64 outwardly against the brake drum 72, thereby to lock the discharge chute 26 against rotation on its turning axis 30. Venting of the brake cylinder 68 permits inward retraction of the brake shoe 64 out of contact with the brake drum 72, under the action of the brake shoe springs 70, thereby releasing the discharge chute for free rotation on its turning axis.

Referring now to FIGURE 2, it will be observed that hydraulic fluid is supplied to the brake cylinder 68 of the brake mechanism 34 from an air boosted hydraulic cylinder 78. The air side of this cylinder receives air under pressure from an air supply line 80, through an air pressure regulator 82 and a two position solenoid valve 84. One terminal of the solenoid valve is grounded. The other terminal of the solenoid valve is connected to the ignition system of the truck to a pair of normally open switches 86, and 88 arranged in electrical parallel. Op-

t eration of either switch to its closed position, therefore, energizes the valve to move the latter to one position thereof. Operation of both switches to their open positions de-energizes the valve to move the valve to its other position. In one position of the solenoid valve, the latter communicates the air inlet of the booster cylinder 78 to the high pressure airline 88, thereby engaging the brake mechanism 34 to lock the discharge chute in fixed angular position on its turning axis 38. In its other position, the solenoid valve communicates the air inlet of the booster cylinder to a vent line leading from the valve, thereby releasing the brake mechanism to permit free rotation of the chute on its turning axis. It is apparent that the solenoid valve may be so connected that the energizing of the valve either engages or releases the brake mechanism. It is preferred, however, to connect the valve in such a way that the brake mechanism is engaged in response to deenergizing of the valve by opening of both switches 86 and 88, so that the discharge chute 26 will be normally locked against rotation when the valve is de-energized.

The brake control switches 86 and 88 are located at convenient positions on the truck 12. For example, the brake control switch 86 may be located in the cab truck for operation by the truck driver when he is seated in the cab. The other brake control switch 88 is shown to be located at the rear of the truck, adjacent the chute 26. It is obvious, of course, that other switch locations are possible and that only one brake control switch or additional brake control switches may be provided.

Those versed in the art will appreciate that the present invention achieves the objects and realizes the advantages hereinbefore mentioned,

Although a specific embodiment of the present invention has been illustrated and described herein, it will be understood that the same is merely exemplary of presently preferred embodiments capable of attaining the objects and advantages hereinbefore mentioned, and that the invention is not limited thereto; variations will be readily apparent to those versed in the art, and the invention is entitled to the broadest interpretation within the terms of the appended claims.

The inventor claims:

1. In a transit concrete mixer including a vehicle, a mixing drum rotatably mounted on said vehicle and having an opening in one end, means for selectively driving said drum in one direction of rotation to mix a concrete slurry in the drum, and in the opposite direction of rotation to discharge the slurry through said drum opening, and a conveyer chute rotatably mounted at one end on said vehicle for turning about a normally vertical axis and having said one end disposed to receive concrete slurry discharged through said drum opening, the improvements comprising:

a brake mechanism mounted on said vehicle and operatively connected to said chute for releasably locking the chute against rotation on said axis, and

remote control means operatively connected to said brake mechanism for engaging and releasing said mechanism from a convenient location on said vehicle spaced from said brake mechanism.

2. In a transit concrete mixer including a vehicle, a mixing drum rotatably mounted on said vehicle and having an opening in one end, means for selectively driving said drum in one direction of rotation to mix a concrete slurry in the drum and in the opposite direction of rotation to discharge the slurry through said drum opening, and a conveyer chute rotatably mounted at one end on said vehicle for turning on a normally vertical axis and having said one end disposed to receive concrete slurry discharged through said drum opening, the improvements comprising:

a brake mechanism including a shaft mounted on said vehicle for turning on an axis approximately aligned with said first mentioned turning axis, a strut connecting said shaft and said chute, whereby rotation of said chute about said turning axis thereof rotates said shaft, and brake means operatively connected to said shaft for releasably locking said shaft against rotation, thereby to lock said chute against rotation on said turning axis thereof, and

remote control means operatively connected to said brake mechanism for engaging and releasing said brake means from a convenient location on said vehicle spaced from said brake mechanism.

3. In a transit concrete mixer including a vehicle, a mixing drum rotatably mounted on said vehicle and having an opening in one end, means for selectively driving said drum in one direction of rotation to mix a concrete slurry in the drum and in the opposite direction of rotation to discharge the slurry through said drum opening, and a conveyer chute having one end rotatably mounted on said vehicle for turning on a normally vertical axis and having said one end disposed to receive concrete slurry discharged through said drum opening, the improvements comprising:

a brake mechanism including a shaft rotatably mounted on said vehicle for turning on an axis approximately aligned with said first mentioned turning axis, a strut connecting said shaft to said conveyer chute, whereby rotation of said chute about said turning axis thereof rotates said shaft, and an hydraulically actuated brake means operatively connected to said shaft for locking the latter against rotation, thereby to lock said chute against rotation on said turning axis thereof, and

a hydraulic control system operatively connected to said brake mechanism for controlling the latter including a control member mounted in a convenient position on said vehicle remote from said brake mechanism for selectively engaging and releasing said brake means.

4. The combination according to claim 3 wherein:

said hydraulically actuated brake means comprise a brake drum fixed to said shaft, a supporting member fixed to said vehicle, brake shoes pivotally mounted on said supporting member for movement into frictional engagement with said brake drum, and a hydraulic cylinder operatively connected between said brake shoes and adapted to be supplied with hydraulic fluid under pressure for urging said brake shoes into frictional contact with said brake drum.

5. A transit concrete mixer including a vehicle, a mixing drum rotatably mounted on said vehicle and having an opening in one end, means for selectively driving said drum in one direction of rotation to mix a concrete slurry in the drum and in the opposite direction of rotation to discharge the slurry through said drum opening, and a conveyer chute having one end rotatably mounted on said vehicle for turning about a normally vertical axis and having said one end disposed to receive concrete slurry discharged through said drum opening, improvements compnsmg:

a brake mechanism including a shaft rotatably mounted on said vehicle below said one end of said chute for turning on an axis approximately aligned with said turning axis of the chute, a strut connecting the lower end of said shaft to the lower end of said chute in such manner that rotation of said chute about said turning axis thereof rotates said shaft, a brake drum fixed to the upper end of said shaft, a supporting plate surrounding the upper end of said shaft below said brake drum and fixed to said vehicle, brake shoes pivotally mounted on said plate, and a hydraulic cylinder operatively connected between said brake shoes and adapted to be supplied with hydraulic fluid under pressure for urging said brake shoes into frictional braking engagement with said brake drum to lock said shaft against rotation and thereby lock said conveyer chute against rotation about said turning axis thereof, and

a hydraulic control system operatively connected to said brake mechanism for controlling the latter including a valve for effecting selective admission of hydraulic fluid to and venting of said brake cylinder, and means connected to said valve for operating the latter from a convenient position on said vehicle.

6. The combination according to claim 5, wherein:

said vehicle includes a drivers cab, and said valve operating means includes a valve operating member mounted in said cab for operation by a vehicle driver seated in said cab.

7. The combination according to claim 6, wherein:

said vehicle includes a drivers cab, and said valve operating means includes a first valve operating member mounted in said cab for operation by a vehicle driver seated in said cab and a second valve operating member mounted on said vehicle adjacent said conveyer chute, and said valve operating members being operatively connected in parallel to said valve, whereby said valve may be controlled by either of said valve operating members.

References Cited by the Examiner UNITED STATES PATENTS 2,705,134 3/1929 Jerner 259-172 3,175,811 3/1965 Jackson 259-172 3,185,450 5/1965 Duecy 259172 3,198,495 8/1965 Maxon 259-172 WALTER A. SCHEEL, Primary Examiner.

R. W. JENKINS, Assistant Examiner. 

1. IN A TRANSIT CONCRETE MIXER INCLUDING A VEHICLE, A MIXING DRUM ROTATABLY MOUNTED ON SAID VEHICLE AND HAVING AN OPENING IN ONE END, MEANS FOR SELECTIVELY DRIVING SAID DRUM IN ONE DIRECTION OF ROTATION TO MIX A CONCRETE SLURRY IN THE DRUM, AND IN THE OPPOSITE DIRECTION OF ROTATION TO DISCHARGE THE SLURRY THROUGH SAID DRUM OPENING, AND A CONVEYOR CHUTE ROTATABLY MOUNTED AT ONE END ON SAID VEHICLE FOR TURNING ABOUT A NORMALLY VERTICAL AXIS AND HAVING SAID ONE END DISPOSED TO RECEIVE CONCRETE SLURRY DISCHARGE THROUGH SAID DRUM OPENING, THE IMPROVEMENTS COMPRISING: A BRAKE MECHANISM MOUNTED ON SAID VEHICLE AND OPERATIVELY CONNECTED TO A CHUTE FOR RELEASABLY LOCKINT THE CHUTE AGAINST ROTATION ON SAID AXIS, AND REMOTE CONTROL MEANS OPERATIVELY CONNECTED TO SAID BRAKE MECHANISM FOR ENGAGING AND RELEASING SAID MECHANISM FROM A CONVENIENT LOCATION ON SAID VEHICLE SPACED FROM SAID BRAKE MECHANISM. 